Sorry I haven't had time to get on the forums for a couple of days.
Derrel... I noticed you side-stepped my comment. I take it you concede that the lens has a problem and Nikon doesn't really make the best of everything? That was just ONE example... there are others. Keep in mind that the price you pay for that Nikon 70-200 is so high... you could buy a whole DSLR with the leftover money you'd have if you had bought a Canon DSLR with a Canon 70-200mm lens (a better lens by any method of measurement). This isn't an isolated case... the same is true of the Canon 24-70 vs. the Nikon 24-70... the Canon lens is not just a better lens... it's also a considerably less expensive lens (I'm checking
B&H as I write this... the Canon is currently about $1700 vs. the Nikon at about $2400). It's not like I'm picking on some obscure lenses (both companies probably have 75+ lenses in the lineup) that nobody really uses... the 24-70 f/2.8 lenses and 70-200 f/2.8 lenses are kinda the top of the heap w.r.t. lens kits.
I hope we've settled the question of lenses. (as they say in Monte Python... "now go away or I shall taunt you a second time")
But then you brought up sensors... (while conveniently NOT responding to the lens topic I brought up). So I guess I need to talk about sensors.
I have to start off by noticing that it's a bit ironic that you should even bring up sensors at all in the context of "Nikon". Which Nikon camera made today actually has a Nikon sensor in it? ('nuff said on that topic.)
And then of course there's the problem with Sony's sensors.
I find that the overwhelming majority of camera owners (even highly experienced camera owners and professionals at the top of their field) don't seem to know how sensors really work.
So far as I'm aware, Sony uses "ISO invariant" sensors (a bit of misnomer... but what it really means is they don't apply any upstream gain). But Sony's sensors aren't actually any better than anyone elses'... it's that Sony aggressively cooks their "RAW" files (there's really no such thing as a "RAW" file from Sony... there's a file they'll tell you is "RAW" ... but it's cooked... heavily.)
Here's just ONE such article (there are many):
https://petapixel.com/2017/05/04/star-eater-issue-no-longer-recommend-sony-cameras-astrophotography/
It's worth pointing out that I was not aware of the above problem until I got into astrophotography and got to know other astrophotographers. It was noticed that astrophotos taken with Nikons were missing stars. This isn't just a DSLR vs. DSLR comparison... there are guys who use relatively high end ($15-20k and up) CCD imaging cameras with cooling systems (when you're taking photos where just one exposure lasts the better part of an hour... cooling is a thing.) The stars weren't missing in images taken with other cameras.
The math of how you can tell if your camera company is cooking your RAW images is fairly easy... but catching them doing it may require writing a bit of code.
The idea is this:
- Put the lens cap on the camera (or remove the lens and attach the body cap) so that no light can enter the camera.
- Set the camera to ISO 100 (or whatever you'd like to use as a base ISO)
- Take an exposure (a few seconds should suffice)
You should get a completely black image because you guaranteed no light could enter the camera. But you wont. What you really have is an "image" that has no signal... and all noise. (A poor signal to noise ratio).
This gets a bit complicated because you also need to work out what your sensor's bias level is (basically take about 50 exposures at the fastest possible shutter speed) ... but this is a bit of a digression from the topic so I wont get into bias levels in this thread. I'm just mentioning it for completeness.
Here's where the code/math comes in.
What you need to do is read the image data from the "RAW" file ... one photo-site at a time... and compute the statistical mean & standard deviation for this "dark" frame. If there is no noise, the standard deviation should be very tiny.
(Doing this requires that you know some details about the format of the RAW file and how to mine the image data out of it.)
So now you have one sample mean & std. dev.... now bump up the ISO, take more images, re-compute the mean & std. dev. and watch what happens.
ISO isn't really part of exposure because it's applied as a post-image-capture step. So whatever data was captured when the shutter was closed is whatever the data was. That part can't change. Only the data as a result of applying ISO gain will change.
But if you apply the gain uniformly, then the ratio for the mean & std. dev. SHOULD remain (scaling linearly with the ISO). But what happens when camera companies "cook" the data is that you wont get a linear graph (and it turns out if you actually do this... you don't get a linear graph). The RAW data is being cooked.
It's also possible to cook even an image at base ISO that would have had low noise anyway.
This was easiest to detect when looking at the difference between a Nikon D810 ... and a Nikon D810
a (the astrophotography edition of the same camera... same sensor... only the filter and firmware are different.)
When you do this, the Nikon D810a completely falls apart compared to a D810 in terms of how wonderful those Nikon sensors (really Sony sensors) are. At the time, I think the current Canon full-frame standard was the 5D III. And even when you use DxO's data ... there's virtually no difference between Canon and Nikon.
So you should probably stop talking about Canon's out-dated sensor technology because it isn't true. (BTW, Canon cooks their data too... just not nearly to the extreme of Nikon & Sony.) As a consequence, Canon is the most popular DSLR (by far) for astrophotography. I don't know anyone who uses Sony and only a few use Nikon.
The Nikon users have problems... no exposure simulation in live-view (which makes manual focus in astrophotography a royal pain in the @#$@ because the camera sees nothing but the blackness of space and thinks it needs to massively boost what it shows in liveview and that totally bloats out what you're trying to focus on to the point where you just can't tell if it's focused.) Nikon blocks use of SDKs on their D3xxx series models (a few people have reversed-engineered enough of it) but as a result, anyone who wants to do astrophotography with a Nikon really needs to make sure that they buy "at least" a D5xxx series model or higher in order to have software support.
Make no mistake... I'm not telling people they need to run out and buy Canon cameras. I don't care which camera people buy. Nikon & Sony make great cameras too. Know what you want to do with the camera and why you're picking a model that suits your needs... great!
But PLEASE don't try to push that Nikon cameras are somehow "better" than the others... that's a load of hooey and it can be demonstrated over and over again. Continued belief in something after it has been shown to be demonstrably false... is called a "delusion".
As a general rule... I stay out of the "my ___ is better than your ____" wars. But you over-stepped by saying Canon has problems with their lenses and I generally don't let people get away with saying things that are patently untrue.
Are we done with this?
